Prepare Strawberry Jam: In a medium pot, combine quartered fresh strawberries, granulated sugar, and lemon juice. Bring to a simmer over medium heat, stirring occasionally for about 15-17 minutes. Remove from heat and let it cool completely.

Mix Dry Ingredients: Sift together the cake flour, baking powder, baking soda, and salt in a large bowl. Set aside.

Cream Butter and Sugar: In a separate large bowl, beat the softened unsalted butter and granulated sugar with an electric mixer on medium speed for about 2-3 minutes until fluffy and pale.

Blend Wet Ingredients: Add in the egg whites and vanilla extract and mix until smooth, about one minute.

Combine Dry & Wet Ingredients: Gradually pour in the buttermilk and dry ingredients mixture, mixing gently until just combined.

Bake Cupcakes: Preheat your oven to 350°F (175°C) and line a cupcake pan with liners. Fill each liner about 2/3 full and bake for 16-18 minutes until a toothpick comes out clean. Cool in the pan for 10 minutes before transferring to a wire rack.

Make Cream Cheese Frosting: Beat the softened butter until fluffy, about 2 minutes. Gradually add the cream cheese and sifted powdered sugar until smooth. Fold in the ground freeze-dried strawberries.

Assemble Cupcakes: Remove the center of each cupcake and fill with strawberry jam, then pipe on the strawberry cream cheese frosting.